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Cesarean Scar DefectB-FINDNCT07634679

Impact of a Bladder Flap on Cesarean Scar Niche Development

A study testing Bladder flap formation in people with Cesarean Scar Defect, run by Montefiore Medical Center at 2 sites in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The goal of this trial is to examine if the completion or omission of a bladder flap impacts the location and formation of cesarean scar niche in women undergoing primary cesarean section. Read more about this study

Who is it for?
Ages 18 years and older, women only
Conditions the study is for
Cesarean Scar Defect
What is being tested?
Bladder flap formation
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
338 participants
Where
2 sitesUnited States
Study dates
3 Oct 2026to 1 Aug 2032
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age 18 years or older
  • Primary low transverse cesarean section performed at Montefiore Weiler or Wakefield Hospitals
  • Able to provide informed consent in English or Spanish
  • Plan for postpartum care at Montefiore Medical Center

Who cannot join

  • History of a prior uterine surgery
  • Known congenital uterine anomalies
  • Inability to safely access lower uterine segment at time of delivery
  • Hysterotomy is extended past/outside the lower uterine segment at time of surgery
  • Hysterectomy is indicated prior to postpartum follow-up

Trial locations and contacts

2 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Alyssa Yeung, MD contact

574-329-8771

ayeung@montefiore.org

United States2 sites, 2 recruiting
  • Jack D. Weiler Hospital - Einstein Campus

    The Bronx, New York, 10461

    Alyssa Yeung, MD, 574-329-8771, ayeung@montefiore.org

    Recruiting
  • Montefiore Einstein Hospital - Wakefield Campus

    The Bronx, New York, 10466

    Alyssa Yeung, MD, 574-329-8771, ayeung@montefiore.org

    Recruiting

Other trials in United States

About this study

The goal of this trial is to examine if the completion or omission of a bladder flap impacts the location and formation of cesarean scar niche in women undergoing primary cesarean section. The main question it aims to answer is if omission of a bladder flap changes the prevalence of cesarean scar niche on a 6-8 week postpartum ultrasound. Researchers will compare participants that have a bladder flap made to those that have a bladder flap omitted at time of their primary cesarean delivery. Participants will have routine postpartum care and be asked to return for a 6-8 week postpartum transvaginal ultrasound.

Read the detailed description

As the rate of cesarean deliveries increases globally, the importance of a cesarean scar niche (CSN) has evolved into a significant clinical concern with long term obstetric and gynecologic implications including increasing risk for placenta accreta spectrum (PAS) in future pregnancies and abnormal uterine bleeding. In fact, the main cause of PAS is placentation into uterine scars secondary to cesarean deliveries

Bladder flap formation is a standard step in cesarean deliveries and involves dissecting the bladder off the uterus to push it inferiorly to allow better access to the lower uterine segment for hysterotomy and decrease risk of bladder injury. The lower uterine segment is targeted for hysterotomy as it has been shown that the proportion of muscle tissue and the thickness of the wall of the uterus increases as one travels from the cervix to the fundus. Therefore, by making an incision in the lower uterine segment, the surgeon has less tissue to go through to deliver the fetus and disrupts less muscle to preserve uterine myometrial integrity. While studies have suggested bladder flap omission in primary cesarean deliveries does not increase intraoperative complications and reduces operating time. CSN assessment was not an outcome evaluated in these studies and the decision to omit or perform a bladder flap is at the discretion of the surgeon.

Previous studies have looked at different surgical techniques and different cervical dilations at time of cesarean delivery and the impact on niche formation and location. There has been no consensus on hysterotomy or other surgical techniques to decrease risk of CSN formation. To our knowledge, there have not been studies that have assessed postoperative CSN in relation to completion or omission of a bladder flap prior to hysterotomy. As such, the investigator team hypothesizes that omission of a bladder flap lends itself to a more cephalad hysterotomy and potentially more clinically significant CSNs.

Being tested
Bladder flap formation
Keywords
Isthmocele

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Bladder flap formationProcedure or surgery

    Participants in this arm will have a bladder flap completed at the time of their cesarean delivery.

Study groups in NCT07634679
Study groupRoleWhat they receive
Bladder flap omissionNo interventionParticipants randomized to this arm will have the bladder flap step omitted prior to low transverse hysterotomy formation. Participants will not need to alter their postoperative or postpartum care.
Bladder flap formationExperimentalParticipants randomized to this arm will have a bladder flap formed using standard procedure during the cesarean delivery prior to low transverse hysterotomy and delivery of the infant. As with the 'Bladder flap omission' arm, participants will not need to alter their postoperative or postpartum care.
Receives: Procedure: Bladder flap formation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Presence of cesarean scar niche

    A dichotomous measure of the presence or absence of a cesarean scar niche, as defined by a residual myometrial thickness of <3mm at the scar level, detected on transvaginal ultrasound. The presence of a cesarean scar niche increases risk for gynecologic complaints and abnormal placentation in subsequent pregnancies.

    Measured: From enrollment to transvaginal ultrasound, completed approximately 6-8 weeks postpartum

Secondary outcomes (7)
  1. Distance of cesarean scar niche from internal os

    Sonographic distance of cesarean scar niche from internal cervical os, measured in millimeters, on postpartum transvaginal ultrasound. The investigator team hypothesizes that a scar further from the internal os has increased risk for abnormal placentation in future pregnancies.

    Measured: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

  2. Size of cesarean scar niche

    Sonographic dimensions of length and width of cesarean scar niche, measured in mm, on transvaginal ultrasound. The investigator team hypothesizes that larger niches are associated with increased risk of abnormal placentation in future pregnancies and increased risk of future gynecologic complaints.

    Measured: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

  3. Measurement of residual myometrium

    Sonographic measurement of residual myometrium in mm by transvaginal ultrasound. Thinner residual myometrium may imply a larger defect, increased risk for abnormal placentation or formation of a uterine window in future pregnancies.

    Measured: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

  4. Size of cesarean scar defect in subsequent pregnancy

    Sonographic measurement of dimensions (length and width) of cesarean scar defect in subsequent pregnancy, measured in mm, to assess if larger postpartum niches are associated with larger defects in subsequent pregnancies as they may carry increased risk of morbidity in the pregnancy.

    Measured: From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy

  5. Cases of abnormal placentation in subsequent pregnancies

    If encountered in a subsequent pregnancy, the number of cases of abnormal placentation in the cesarean scar and placenta accreta spectrum will be summarized. Ultrasound evidence of placenta accreta spectrum include disappearance of the border between placenta and myometrium, placental lacunae, increased vasculature from placenta extending into myometrium, abnormal invasion of placenta into surrounding organs and structures. Pathology will be used to confirm the number of cases of placenta accreta spectrum.

    Measured: From time of enrollment to time of subsequent pregnancy, up to 5 years following baseline pregnancy

  6. Uterine Position/Flexion

    As an anteverted and retroflexed uterus is commonly the result of a cesarean delivery and scar tissue altering anatomical position, the clinicians will observe if a bladder flap alters position of the uterus. At the 6 week transvaginal ultrasound, the position of the uterus as anteverted or retroverted and flexion as anteflexed or retroflexed will be recorded. In the sagittal plane on transvaginal ultrasound, if the cervix appears on the viewer's right or left, the position is anteverted or retroverted, respectively. The anterior or posterior flexion of the fundus will define anteflexion and retroflexion, respectively

    Measured: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

  7. Number/percentage of Operative and Postoperative Complications

    Patient charts will be reviewed to summarize the number/percentage of surgical complications in each arm. This includes complications such as damage to surrounding structures, hemorrhage, hematoma formation, surgical site infections.

    Measured: From enrollment to time of transvaginal ultrasound, completed approximately 6-8 weeks postpartum

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted9 Jun 2026
  2. Study start3 Oct 2026
  3. Primary completion1 Sep 2027 (estimated)
  4. Study completion1 Aug 2032 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Participants will be randomized in a 1:1 ratio into two treatment groups one undergoing bladder flap formation and the other undergoing bladder flap omission
Masking
None (open label)
Enrolment
338 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07634679
Sponsor's protocol ID
2025-17472
Other IDs
2025
Acronym
B-FIND
Status last verified
Oct 2026
First submitted
4 Jun 2026
Last updated
7 Oct 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: De-identified individual participant data (IPD) that underlie the results reported in future publications will be made available to qualified researchers upon request

Publications

  • Kamel R, Thilaganathan B. Time to reconsider elective Cesarean birth. Ultrasound Obstet Gynecol. 2021 Mar;57(3):363-365. doi: 10.1002/uog.22158. No abstract available.

    PubMed 33220003
  • Kamara M, Henderson JJ, Doherty DA, Dickinson JE, Pennell CE. The risk of placenta accreta following primary elective caesarean delivery: a case-control study. BJOG. 2013 Jun;120(7):879-86. doi: 10.1111/1471-0528.12148. Epub 2013 Feb 28.

    PubMed 23448347
  • Shi XM, Wang Y, Zhang Y, Wei Y, Chen L, Zhao YY. Effect of Primary Elective Cesarean Delivery on Placenta Accreta: A Case-Control Study. Chin Med J (Engl). 2018 Mar 20;131(6):672-676. doi: 10.4103/0366-6999.226902.

    PubMed 29521289
  • O'Neill HA, Egan G, Walsh CA, Cotter AM, Walsh SR. Omission of the bladder flap at caesarean section reduces delivery time without increased morbidity: a meta-analysis of randomised controlled trials. Eur J Obstet Gynecol Reprod Biol. 2014 Mar;174:20-6. doi: 10.1016/j.ejogrb.2013.12.020. Epub 2013 Dec 22.

    PubMed 24411951
  • Tuuli MG, Odibo AO, Fogertey P, Roehl K, Stamilio D, Macones GA. Utility of the bladder flap at cesarean delivery: a randomized controlled trial. Obstet Gynecol. 2012 Apr;119(4):815-21. doi: 10.1097/AOG.0b013e31824c0e12.

    PubMed 22395144
  • Fukuda M, Fukuda K, Shimizu T, Bujold E. Ultrasound Assessment of Lower Uterine Segment Thickness During Pregnancy, Labour, and the Postpartum Period. J Obstet Gynaecol Can. 2016 Feb;38(2):134-40. doi: 10.1016/j.jogc.2015.12.009. Epub 2016 Mar 2.

    PubMed 27032737
  • Rorie DK, Newton M. Histologic and chemical studies of the smooth muscle in the human cervix and uterus. Am J Obstet Gynecol. 1967 Oct 15;99(4):466-9. doi: 10.1016/0002-9378(67)90292-x.

    PubMed 4167498
  • Kamel R, Eissa T, Sharaf M, Negm S, Thilaganathan B. Position and integrity of uterine scar are determined by degree of cervical dilatation at time of Cesarean section. Ultrasound Obstet Gynecol. 2021 Mar;57(3):466-470. doi: 10.1002/uog.22053.

    PubMed 32330331
  • Klein Meuleman SJM, Min N, Hehenkamp WJK, Post Uiterweer ED, Huirne JAF, de Leeuw RA. The definition, diagnosis, and symptoms of the uterine niche - A systematic review. Best Pract Res Clin Obstet Gynaecol. 2023 Aug;90:102390. doi: 10.1016/j.bpobgyn.2023.102390. Epub 2023 Jul 15.

    PubMed 37506497
  • Jauniaux E, Collins S, Burton GJ. Placenta accreta spectrum: pathophysiology and evidence-based anatomy for prenatal ultrasound imaging. Am J Obstet Gynecol. 2018 Jan;218(1):75-87. doi: 10.1016/j.ajog.2017.05.067. Epub 2017 Jun 24.

    PubMed 28599899
  • Angolile CM, Max BL, Mushemba J, Mashauri HL. Global increased cesarean section rates and public health implications: A call to action. Health Sci Rep. 2023 May 18;6(5):e1274. doi: 10.1002/hsr2.1274. eCollection 2023 May.

    PubMed 37216058

Questions about this trial

What is this clinical trial studying?

A study testing Bladder flap formation in people with Cesarean Scar Defect, run by Montefiore Medical Center at 2 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 7 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Alyssa Yeung, MD (574-329-8771, ayeung@montefiore.org), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Presence of cesarean scar niche (time frame: From enrollment to transvaginal ultrasound, completed approximately 6-8 weeks postpartum). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07634679, which also lists 11 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Oct 2026.

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